Lucidafuranocoumarins B and C from the twigs of Feroniella lucida: Absolute configurations of lucidafuranocoumarin C

Two new furanocoumarins, lucidafuranocoumarins B (1) and C (2), were isolated from the twigs of Feroniella lucida, together with five known compounds (3–7). The structures of these compounds were identified on the basis of extensive spectroscopic methods. The absolute configurations of lucidafuranocoumarin C at C-2″ and C-5″ were established as R- and S-configurations, respectively, by applying Mosher's method. Some isolates were also evaluated for their cytotoxicity against KB, MCF-7 and NCI-H187 cell lines.     

Phenylpropanoid derivatives from Clausena harmandiana fruits

A new phenylpropanoid derivative, harmandianone (1), along with four known compounds: verimol B (2), (E)-3-(2-hydroxy-4-methoxy-phenyl)propanoate (3), (E)-methyl p-coumarate (4), and (E)-5-methoxy-2-(prop-1-enyl)phenol (5) was isolated from the acetone extract of Clausena harmandiana fruits. All structures were characterized by spectroscopic methods (UV, IR, NMR and ESI-TOF-MS). Compounds 1 and 3–5 demonstrated weak antibacterial activity against Escherichia coli TISTR 780, methicillin-resistant Staphylococcus aureus SK1, Salmonella typhimurium TISTR 292 and S. aureus TISTR1466, with MIC values between 64 and 128 μg/mL.     

Candenatenins G–K,phenolic compounds from Dalbergia candenatensis heartwood

Five new phenolic compounds, designated candenatenins G–K (1–5), along with four known compounds, were isolated from the heartwood of Dalbergia candenatensis. The structures of these compounds were elucidated by HR-EI-MS, ¹H and ¹³C NMR, COSY, HMQC, HMBC, and NOESY spectra. Compound 5 exhibited potent activity against DPPH radical scavenging with IC₅₀ value of 25.7 μM, whereas compound 2 showed cytotoxicity against NCI-H187 cell line with IC₅₀ value of 14.8 μM.     

Xanthones from the stem bark of Garcinia nigrolineata

Nine xanthones, nigrolineaxanthones A-I, together with nine known xanthones, were isolated from the crude methanol extract of the stem bark of Garcinia nigrolineata; two of which have previously been reported as synthetic xanthones. The structures were elucidated by analysis of spectroscopic data, especially using 1D and 2D NMR spectroscopic data.     

Glycopentaphyllone: The first isolation of hydroperoxyquinolone from the fruits of Glycosmis pentaphylla

A new hydroperoxyquinolone alkaloid, glycopentaphyllone (1), along with nine compounds (2–10), was isolated from the fruits of Glycosmis pentaphylla. Their structures were elucidated on the basis of spectroscopic methods. The absolute configuration of glycopentaphyllone at C-2′ was established as S-configuration by applying Mosher's method. In addition, the completed assignments of ¹³C NMR as well as 2D NMR spectral data of compound 5 were reported herein for the first time. Also, all isolates were evaluated for antibacterial activity against Escherichia coli TISTR 780, Salmonella typhimurium TISTR 292, Staphylococcus aureus TISTR 1466, and Methicillin-resistant S. aureus SK1.     

Carbazole alkaloids and coumarins from Clausena lansium roots

Two new carbazole alkaloids, mafaicheenamines D (1) and E (2), together with twelve known compounds (3–14) were isolated from the roots of Clausena lansium. Spectroscopic methods, including NMR, UV, IR, and MS spectral data were used for structural characterization. Some of isolates were evaluated for their cytotoxicity against three human cancer cell lines (KB, MCF-7, and NCI-H187).     

Alkaloids from Glycosmis cochinchinensis twigs

A phytochemical investigation of the twigs of Glycosmis cochinchinensis led to the isolation of two new alkaloids, glycosmisacridone (1) and glycosmisindole (2), together with eight known compounds (3–10). Their structures were elucidated by intensive analysis of their spectroscopic data. Compound 9 exhibited moderate antibacterial activity against methicillin-resistant Staphylococcus aureus SK1with an MIC value of 16 μg/mL.